Convertible boat

ABSTRACT

This invention relates to a boat hull provided with improved flap or vane means at the stern portion of the hull for use in converting the hull in an expeditious and simplified fashion from one type of boat hull to another type of boat hull, such as a sailboat hull to a hydroplane hull and vice versa.

United States Patent Flink 51 July 25,1972

[ CONVERTIBLE BOAT John W. Flink, 1690 Mulberry Lane, San Jose, Calif. 95125 [22] Filed: June 15, 1970 [21] Appl.No.: 46,231

[72] Inventor:

521 US. Cl ..114/66.5 P

[51] Int. Cl ..B63b H28 [58] Field of Search ..l 14/665 P 56] References Cited UNITED STATES PATENTS Bloomfield et a1 ..l 14/665 P X 1,755,709 4/1930 Small ..l l4/66.5 P 2,347,841 5/1944 Parker... l14/66.5 P X 3,456,610 7/1969 Beals ..l l4/66.5 P

Primary Examiner-Andrew H. Farrell Attorney-Katherine Lloyd [57] ABSTRACT This invention relates to a boat hull provided with improved flap or vane means at the stern portion of the hull for use in converting the hull in an expeditious and simplified fashion from one type of boat hull to another type of boat hull, such as a sailboat hull to a hydroplane hull and vice versa.

7 Claims, 6 Drawing Figures Patontod July 25, 1972 2 Sheets-Sheet 1 INVENTOR. JOHN w. FLINK AGENT Fatentoc l July 25, 1 972 I v 2 Shoots-Shut Z INVENTOR. JGHN W F LINK AGE N T CONVERTIBLE BOAT BACKGROUND OF THE INVENTION Heretofore various vane devices have been proposed for attachment to boat hulls, such as the vanes or flaps affixed to hydroplane hulls for use in bringing the hull to a full planing position or as trim tabs for correcting the listing and/or improving the planing action of a boat hull as it moves through water. These devices, however, have ordinarily taken the form of small individual tabs or vanes which did not extend entirely across the beam of the boat. They are ineffective in converting a single hull of one configuration to another hull. They lacked the overall continuity and expanse of the flap of the instant invention which presents a sufficient amount of surface area to the water so as to be truly effective in breaking the suction of the water on the stern portion of a sailing hull and in elevating it to the desired planing position. In addition, the small sizes and locations of these prior art flaps meant that they had to be constantly attended to in order to keep the hull properly trimmed at all times. All of this detracted from the recreational pruposes and designs of hulls equipped with such flaps. Finally, these prior specially designed hulls were also usually of complex and expensive structure and meant that a person desiring to enjoy the pleasures of sailing and hydroplaning had to buy two boats instead of one. The device of this invention is also useful for water-skiing, fishing and other boating operations. The prior art noted above applies especially to motorboats.

BRIEF SUMMARY OF INVENTION This invention relates to boat hulls provided with an improved hydroplane type vane or flap. More particularly, it is concerned with providing a boat hull equipped with improved flap or vane means pivotally affixed to the bottom hull adjacent the stem portion whereby the boat hull can be simply and readily converted from a hull of one type of boat to that of another type of boat. Thus, for example, by proper manipulation of the improved vane or flap device of the instant invention a sailboat hull can be converted to a motorboat hull and vice versa in a simple and expeditious fashion. This also means that for a relatively small investment of money a person can enjoy the pleasures of both motorboating and sailing while buying but one boat hull and providing one storage area for the same instead of having to buy two entirely different kinds of boats and of having to provide separate storage for each.

In one advantageous embodiment of the invention, the flap or vane device has such dimensions that, when it is in a fully extended position, it extends lengthwise substantially entirely across the width of the boat and from the area on the bottom of the boat where the chine lines recede upwardly in a sailing hull rearwardly to a point which is slightly offset outwardly from the normal plane of the transom of the hull when the said transom plane is projected downwardly to intersect the plane of the extended flap device. By virtue of such a preferred construction for the flap or vane, a simple and expeditious means has been provided for converting a hull primarily designed as a sailboat hull to one fully capable of acting as a hydroplane and motorboat. This can be effected without having to remove the hull from the water and putting the same in a dry dock. This is a decided advantage when it is realized that sailboat hulls differ radically from motorboat or hydroplane hulls, particularly in that the chine lines recede upwardly at the stern portion of the hull in a sailing hull, whereas in a hydroplane type of hull, the chine lines extend to the stern approximately parallel with the rail of the hull.

DESCRIPTION OF THE DRAWINGS The various advantages of the instant invention will become more apparent by reference to the following drawings, wherein:

FIG. 1 is a side elevational view of a sailboat type hull provided with the improved stern flap device of the instant invention;

FIG. 2 is a cross-sectional view taken on line 2-2 of FIG. 3,

with the flap device being shown in cross-section in its retracted position and in dotted lines in its extended hydroplaning position;

FIG. 3 is an end elevational view of the transom of the boat hull shown in FIG. 1.

FIG. 4 is an enlarged fragmentary sectional view taken generally along line 5-5 of FIG. 3 and illustrates one means for anchoring a control rod to the flap device;

FIG. 5 is a fragmentary perspective view of the bottom and stem part of the boat hull of Fig. I; and

FIG. 6 is a fragmentary sectional view taken within the circumscribing line 6-6 of FIG. 5 and illustrates the manner in which a flap element can be pivotally affixed or attached to the boat hull in the area of the stern.

DETAILED DESCRIPTION With further reference to the drawings, the planing device of the instant invention preferably comprises a pair of flaps l2 and 14 which are pivotally afiixed to the bottom ll of a sailing boat hull l6 and each of which extends from the keel center line substantially to the side 13 or 13' or chine lines 20 of the boat. Suitably, each flap l2 and 14 is affixed to the bottom of the hull by means of a piano hinge 50 of corrosion-resistant metal as shown especially in FIGS. 6 and 7. The flaps are best located so that the forward edge extends from a point on the keel center line to a point on the chine line which points are at the same level below a horizontal plane through the center line of the floor of the boat at the point where the chine lines begin to recede or slant upwardly. In other words, the juncture of the forward edge of the flaps with the keel center line and that with the chine line are at the above-mentioned level. As shown in FIG. 6, this results in a dihedral angle between the flap forward edges, in the preferred embodiment. A metal plate 18 is suitably riveted to or otherwise attached to the inboard edge of one flap adjacent the trailing edge whereby when the flaps are down in planing position any open space between the inboard edges of the flaps is covered by such plate. Preferably such metal also covers the keel center line from the juncture with the flaps to the stem of the boat, except for the center-board opening. Suitably, each flap 12 or 14 has a reinforcing bar 15 at its top trailing edge to which the control rods can be fixed.

In any event, regardless of whether the flaps comprise at least two integrated elements, or a single element, they should preferably be of such dimensions as indicated in FIGS. 2 and 3 whereby, when they are in a fully extended position, they extend in one direction substantially entirely across the width of the boat from one side chine line 20 to the other chine line 20 and in another direction from the area on the bottom of the boat hull 16 where the chine portions recede upwardly rearwardly to a point which is slightly off-set outwardly from the normal plane of the transom 22 of hull 16 when the transom plane is projected downwardly to intersect the plane of the extended flap device which, in effect, now constitute projections of the chine lines 2020 by virtue of the extended outboard edges 24 of the flap elements 12 and 14.

In other words, the flap elements 12 and 14 when selectively lowered from the retracted position of FIG. 1 act to extend the normal chine lines 20 substantially straight out and preferably to a point at least at the transom line which is the desirable hull structure or condition for motorboating or hydroplaning. When retracted, the flaps parallel the normal chine lines 20 20 of the sailing hull depicted in FIG. I so that the hull 16 when equipped with the usual mast 26 and movable center board 28 sealed to the hull bottom can serve as a true and efficient sailing hull.

In a further advantageous embodiment of the invention and as indicated particularly in FIG. 5, the trailing edges 30 of the flap elements are slightly offset outwardly of the bottom edge 23 of transom 22 in order to accommodate control rods 32 pivotally connected at one extremity thereof to a flap element by pin assemblies 34 and saddles 36 made of brass or other corrosion resistant metal affixed directly to the flaps 12 and 14.

Two or more control rods 32 can be affixed to each flap, In a preferred arrangement for locking control rods 32 in the desired position, the rods are provided with spaced holes 33 adapted to register with a single hole 37 for each rod in transom 22. A bolt 35 threaded at at least one end passes through the hole 37 and a hole 33 and is drawn up and secured by tightening a keeper 40. The holes 33 are suitably spaced, for instance, at such distance to maintain a flap 12 or 14 closely against bottom 11 of the hull for sailing position, or at a proper distance to hold the flap in the extended chine line position for planing. If desired, the flap can be adjusted to a slightly higher or lower than extended chine line position by means of additional holes in rods 32, secured as described. Also if desired, the outboard rods can be retracted to a higher position than the inboard rods to provide a deeper V-configuration to the flaps. In still another embodiment the rods can be lowered and retracted by conventional hydraulic means such as are well-known in operating boat levelers; and, if desired, the rods can be disposed within the boat at the inside of the transom.

The flaps 12 and 14 can be pivotally secured to the bottom of the hull in various ways. As indicated particularly in FIG. 6, they can be advantageously affixed by means of suitable piano-type hinge assemblies 50. In the area where the flaps 12 and 14 join the hull or at the piano hinge-type joints, the piano hinge is countersunk into the supporting flap and tapered section to conform to the contour of the chine line to avoid stepping and built-in turbulence producing element that can cause serious problems with the otherwise smooth flow of water past the hull 16 or adversely affect movement of the hull 16 oradversely affect movement of the hull over the water.

In a preferred dihedral form, the angle of the flaps l2 and 14 is so selected that their junctures with the chine lines 20 20 and the keel center line 16 inches are all at substantially the same .level with respect to a horizontal plane through the center line of the floor of the boat. The angle at the meeting of the flap elements 12 and 14, i.e., the V at the center line can change from about 5 inches at the hinge line to l k inches at the transom in a typical arrangement. The flaps can be made of any suitable material, such as marine plywood, fiberglass, aluminum, etc. or various combinations thereof. One advantageous type is plywood covered with a layer of fiberglass. Although each flap can form a relatively straight line or flat surface, alternatively it may be slightly contoured from front to rear.

It will also be noted by reference to the drawing that the transom 22 can be a reverse sloping and sturdy type transom and have a removable cutaway section at the top to accommodate an outboard motorboat when a motor is attached to a motor mount 21. This sloping construction is advantageous because it helps to support the rods 32 which then rest in part against transom 22 as well as being affixed thereto as described above. In each instance, it will be observed that the flaps 12 and 14 are so arranged as not to interfere with the operation or attachment to the hull 16 of a tiller or motorboat.

As shown in H6. 1, a mast is employed at 26 when the boat hull is used as a sailing hull and the flaps are retracted to the up position. At the same time a rudder and tiller (not shown) are installed at the transom, suitably supported on motor mount 21. When the hull is employed as a hydroplane hull, the mast is removed, along with the tiller and rudder, and a suitable outboard marine motor installed on the motor mount 21. It

is often convenient also to install a wheel just aft of the center.

board, such wheel being connected to control either rudder or motor by a suitable series of wires. Additionally, it is convenient when hydroplaning to install a removable windshield, removably bolted to the top of the boat at its forward portion. The wheel and such windshield are shown in phantom in FIG. 1.

Advantageous embodiments of the invention have been shown and described. It is obvious various changes may be made therein without departing from the appended claims. For instance, the boat shown is made of marine plywood, fiberglass covered, but other materials of construction can be used. The flap device comprises a plurality of flaps located at an angle to each other and one said flap is provided with a metal plate to overlap another said flap and maintain a closed surface. Having described the invention,

What is claimed is:

1, A convertible boat hull provided with a keel center line and chine line side portions which normally recede upwardly and away from the keel centerline at the stern of the hull, means for effecting a simulated projection of said chine side portions downwardly toward the keel center line whereby the hull can be transformed into a hydroplane type hull in the area of the stern, said means comprising a plurality of flap devices, each said flap device being pivotally connected to a selected part of the hull bottom in the area of the stern, said flap devices extending in one direction substantially fully across the boat from chine line to chine line and in another direction rearwardly toward the boat transom, and means for mounting and holding each said flap device in selected extended and retracted positions, said flap devices being located at an angle to each other and one said flap device being provided with a metal plate to overlap an adjacent flap device and maintain a closed surface.

2. The boat hull of claim 1 wherein said flap device is connected to the bottom of the hull in the area of the hull where the chine lines normally recede upwardly away from the keel.

3. The boat hull of claim 1 wherein the'transom is a reverse sloping transom.

4. The boat hull of claim 1 wherein said flap device holding means comprise at least one control rod hingedly affixed at one extremity to each flap device and resting against and removably and selectively locked to a reverse sloping transom.

5. The hull of claim 1 wherein said means effecting a simulated projection of said chine side portions comprises a pair of flaps.

6. In a boat hull having a keel center line, a bottom, a floor, two sides and a chine line at each side slanting upwardly to the stem to enable free flow of water in sailing, the improvement comprising in combination a pair of flaps hinged to said bottom, each said flap being hingedly attached at its forward edge so that the juncture thereof with said chine line and with said keel center line are at substantially the same level with respect to a horizontal plane through the center line of said floor where said chine line begins to slant upwardly, and means to lower said flap to form an angle with said chine line to effect planing when said boat is in motion in water and to raise said flap to lie adjacent said bottom, one said flap being provided with a metal plate to overlap another said flap and maintain a closed surface when said flaps are lowered.

7. A convertible boat hull comprising in combination:

a. a hull having a stern, a bottom, a keel center line, a transom, two sides, a floor, and a chine line at each side slanting upwardly at said stern;

b. a pair of flaps hingedly attached to said bottom, each said flap extending from said keel center line to a chine line, and being attached so that the junctures thereof with said chine lines and with said keel center line are at substantially the same level with relation to a horizontal plane through the center line of said floor where said chine lines begin to slant upwardly; and

c. means to raise said flaps to lie adjacent said bottom to facilitate efficient operation as a sailboat and to lower said flaps to form an angle with said chine lines to effect planing when said hull is motor-driven, one said flap being provided with a metal plate to overlap the other said flap and to maintain a closed surface when said flaps are lowered. 

1. A convertible boat hull provided with a keel center line and chine line side portions which normally recede upwardly and away from the keel centerline at the stern of the hull, means for effecting a simulated projection of said chine side portions downwardly toward the keel center line whereby the hull can be transformed into a hydroplane type hull in the area of the stern, said means comprising a plurality of flap devices, each said flap device being pivotally connected to a selected part of the hull bottom in the area of the stern, said flap devices extending in one direction substantially fully across the boat from chine line to chine line and in another direction rearwardly toward the boat transom, and means for mounting and holding each said flap device in selected extended and retracted positions, said flap devices being located at an angle to each other and one said flap device being provided with a metal plate to overlap an adjacent flap device and maintain a closed surface.
 2. The boat hull of claim 1 wherein said flap device is connected to the bottom of the hull in the area of the hull where the chine lines normally recede upwardly away from the keel.
 3. The boat hull of claim 1 wherein the transom is a reverse sloping transom.
 4. The boat hull of claim 1 wherein said flap device holding means comprise at least one control rod hingedly affixed at one extremity to each flap device and resting against and removably and selectively locked to a reverse sloping transom.
 5. The hull of claim 1 wherein said means effecting a simulated projection of said chine side portions comprises a pair of flaps.
 6. In a boat hull having a keel center line, a bottom, a floor, two sides and a chine line at each side slanting upwardly to the stern to enable free flow of water in sailing, the improvement comprising in combination a pair of flaps hinged to said bottom, each said flap being hingedly attached at its forward edge so that the juncture thereof with said chine line and with said keel center line are at substantially the same level with respect to a horizontal plane through the center line of said floor where said chine line begins to slant upwardly, and means to lower said flap to form an angle with said chine line to effect planing when said boat is in motion in water and to raise said flaP to lie adjacent said bottom, one said flap being provided with a metal plate to overlap another said flap and maintain a closed surface when said flaps are lowered.
 7. A convertible boat hull comprising in combination: a. a hull having a stern, a bottom, a keel center line, a transom, two sides, a floor, and a chine line at each side slanting upwardly at said stern; b. a pair of flaps hingedly attached to said bottom, each said flap extending from said keel center line to a chine line, and being attached so that the junctures thereof with said chine lines and with said keel center line are at substantially the same level with relation to a horizontal plane through the center line of said floor where said chine lines begin to slant upwardly; and c. means to raise said flaps to lie adjacent said bottom to facilitate efficient operation as a sailboat and to lower said flaps to form an angle with said chine lines to effect planing when said hull is motor-driven, one said flap being provided with a metal plate to overlap the other said flap and to maintain a closed surface when said flaps are lowered. 